Re: Fw: [Bug 205469] New: x86_32: bpf: multiple test_bpf failures using eBPF JIT

From: Greg KH <greg@kroah.com>
To: Daniel Borkmann <daniel@iogearbox.net>
Cc: Wang YanQing <udknight@gmail.com>,
	Stephen Hemminger <stephen@networkplumber.org>,
	Alexei Starovoitov <ast@kernel.org>,
	Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Yonghong Song <yhs@fb.com>,
	bpf@vger.kernel.org
Subject: Re: Fw: [Bug 205469] New: x86_32: bpf: multiple test_bpf failures using eBPF JIT
Date: Thu, 21 Nov 2019 21:37:06 +0100	[thread overview]
Message-ID: <20191121203706.GD813260@kroah.com> (raw)
In-Reply-To: <69c1fa5e-7385-fe8d-ac17-42d22db84cf4@iogearbox.net>

On Mon, Nov 11, 2019 at 01:56:31PM +0100, Daniel Borkmann wrote:
> On 11/9/19 7:36 PM, Wang YanQing wrote:
> > On Sat, Nov 09, 2019 at 12:37:49AM +0100, Daniel Borkmann wrote:
> > > [ Cc Wang (x86_32 BPF JIT maintainer) ]
> > > 
> > > On 11/8/19 4:57 PM, Stephen Hemminger wrote:
> > > > 
> > > > Begin forwarded message:
> > > > 
> > > > Date: Fri, 08 Nov 2019 07:35:59 +0000
> > > > From: bugzilla-daemon@bugzilla.kernel.org
> > > > To: stephen@networkplumber.org
> > > > Subject: [Bug 205469] New: x86_32: bpf: multiple test_bpf failures using eBPF JIT
> > > > 
> > > > 
> > > > https://bugzilla.kernel.org/show_bug.cgi?id=205469
> > > > 
> > > >               Bug ID: 205469
> > > >              Summary: x86_32: bpf: multiple test_bpf failures using eBPF JIT
> > > >              Product: Networking
> > > >              Version: 2.5
> > > >       Kernel Version: 4.19.81 LTS
> > > >             Hardware: i386
> > > >                   OS: Linux
> > > >                 Tree: Mainline
> > > >               Status: NEW
> > > >             Severity: normal
> > > >             Priority: P1
> > > >            Component: Other
> > > >             Assignee: stephen@networkplumber.org
> > > >             Reporter: itugrok@yahoo.com
> > > >                   CC: itugrok@yahoo.com
> > > >           Regression: No
> > > > 
> > > > Created attachment 285829
> > > >     --> https://bugzilla.kernel.org/attachment.cgi?id=285829&action=edit
> > > > test_bpf failures: kernel 4.19.81/x86_32 (OpenWrt)
> > > > 
> > > > Summary:
> > > > ========
> > > > 
> > > > Running the 4.19.81 LTS kernel on QEMU/x86_32, the standard test_bpf.ko
> > > > testsuite generates multiple errors with the eBPF JIT enabled:
> > > > 
> > > >     ...
> > > >     test_bpf: #32 JSET jited:1 40 ret 0 != 20 46 FAIL
> > > >     test_bpf: #321 LD_IND word positive offset jited:1 ret 0 != -291897430 FAIL
> > > >     test_bpf: #322 LD_IND word negative offset jited:1 ret 0 != -1437222042 FAIL
> > > >     test_bpf: #323 LD_IND word unaligned (addr & 3 == 2) jited:1 ret 0 !=
> > > > -1150890889 FAIL
> > > >     test_bpf: #326 LD_IND word positive offset, all ff jited:1 ret 0 != -1 FAIL
> > > >     ...
> > > >     test_bpf: Summary: 373 PASSED, 5 FAILED, [344/366 JIT'ed]
> > > > 
> > > > However, with eBPF JIT disabled (net.core.bpf_jit_enable=0) all tests pass.
> > > > 
> > > > 
> > > > Steps to Reproduce:
> > > > ===================
> > > > 
> > > >     # sysctl net.core.bpf_jit_enable=1
> > > >     # modprobe test_bpf
> > > >     <Kernel log with failures and test summary>
> > > > 
> > > > 
> > > > Affected Systems Tested:
> > > > ========================
> > > > 
> > > >     OpenWrt master on QEMU/pc-q35(x86_32) [LTS kernel 4.19.81]
> > > > 
> > > > 
> > > > Kernel Logs:
> > > > ============
> > > > 
> > > > Boot log with test results is attached.
> > > > 
> > 
> > Hi Daniel Borkmann!
> > 
> > I have tested and verified that the report bug has been fixed by commit
> > 711aef1bbf88 ("bpf, x32: Fix bug for BPF_JMP | {BPF_JSGT, BPF_JSLE, BPF_JSLT, BPF_JSGE}")
> > 
> > But that fix hasn't been backport to stable trees, so maybe we should do it:)
> 
> Yes, given you have access to a x32 setup and are also able to runtime test the backported
> JIT changes, please submit it to stable with us in Cc. Thanks Wang!

Backporting this would be nice if someone could do it :)

thanks,

greg k-h